This invention relates to a yarn guiding surface and, more particularly, it relates to a yarn guiding surface of a finish applicator and the method of making such surface.
U.S. Pat. No. 4,397,164 discloses a yarn finish applicator for applying liquid finish to a moving continuous filament yarn. The yarn finish applicator includes a body member that has top, opposed side, front and back surfaces. A slot with bottom and side walls is formed in the front surface running from top to bottom of the body member. The slot has bottom and side walls with a passage connecting with the back surface of the body member through which is metered the desired quantity of liquid finish. The lower portion of the front and back surfaces of the body member are angled downwardly toward each other and in conjunction with the opposed side surfaces which taper downwardly toward each other form an edge at the bottom wall of the slot. The side walls of the slot taper inwardly toward the bottom wall while tapering toward each other at the entrance of the slot. This unique slot configuration not only facilitates placing the moving yarn line in the applicator slot but also prevents the finish from migrating by surface-tension-induced spreading away from the yarn path.
When yarns incorporate additives such as titanium dioxide to produce dull yarn, the yarn becomes abrasive, and when it is passed through such applicators an abrasive action between the yarn and the yarn contacting surface of the applicator occurs, due to the relative movement between the two, which polishes the contacted surface. As a consequence, the friction between the yarn and the contacted surface increases, creating undesirable tension increases in the yarn and a need to frequently replace the applicators.